Ferruginous Rough-leg 179 



tawny wash, often the black massed across the abdomen. Young birds 

 are very similar, but have the basal half of the tail white, the terminal 

 portion dusky brown with a white ti^J, while below the brown is chiefly 

 massed across the belly. In the melanistic phase both young and old 

 are entirely deep black, except for the white forehead, the white on the 

 inner webs of the quills above the notch, and some broken bands on the 

 tail. The two phases are connected by every gradation of intermediate 

 states. Iris brown or yellow, bill bluish-horn, cere and legs yellow, 

 claws black. Length (of a male) 21 ; wing 17'5 ; culmen 1>2 ; tarsus 

 2 7. The female is larger — wing 18-0. 



Distribution. — Breeding in the northern North America, from Alaska 

 and Yukon to the lower St. Lawrence Valley ; south in winter over 

 the greater part of the United States as far south as Virginia and 

 southern CaHfornia, 



In Colorado the Rough-legged Hawlv is not uncomon on the eastern 

 plains, and perhaps in the foothills from November to March, but it has 

 been but little noticed, and definite records are wanting. I have not 

 heard of it on the western slopes. There are several examples in the 

 Aiken collection from El Paso co., one an adult male taken January 

 15th ; and Henshaw also states that he saw several near Colorado 

 Springs in November. Warren informs me that Mr. Hersey shot one 

 near Orchard as late as March 26th. 



Habits. — The Rough-legged Hawk is a peaceful and 

 unoffending bird, which preys chiefly on meadow mice 

 or voles of the Arvicoline group in its winter range, and 

 on lemmings in the far north. As the voles are highly 

 destructive to crops and to fruit trees, especially in 

 winter, this Hawk is undoubtedly a most valuable aid 

 to the farmer, and should be most rigidly protected. 

 It is somwehat crepuscular in its habits, and obtains 

 its prey either by watching from a fixed point or beating 

 to and fro, like the Harrier or Marsh-Hawk, over the 

 meadows with slow and noiseless flight. 



Ferruginous Rough-leg. Archibuteo ferrugineus. 



A.O.U. Checklist no 348— Colorado Records— Ridgway 73, p. 186 ; 

 Henshaw 75, p. 425 ; Allen & Brewster 83, p. 197 ; Drew 85, p. 17 ; 

 Dille 85, p. 44 ; 87, p. 97 ; 03, p. 74 ; Morrison 89, p. 8 ; Kellogg 90, 

 p. 90 ; Bendire 92, p. 259 ; Lowe 97, p. 69 ; Cooke 97, pp. 75, 204 ; 



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